北京地区实验小鼠诺如病毒流行情况

Prevalence of Mouse Norovirus in Experimental Mice in Beijing

目的 调查北京地区19家生物公司自然条件下养殖的实验小鼠感染小鼠诺如病毒(mouse norovirus,MNV)的情况。方法 从19家公司生产的小鼠中随机抽取,每品种品系、每批次14只小鼠合为一笼,共计1 396笼19 544只小鼠。对每笼取粪便样本,采用TaqMan探针荧光定量PCR法,用MNV-1引物检测各品系小鼠感染MNV的情况,根据循环阈(cycle threshold,Ct)值判断小鼠是否被感染;采用卡方检验对5种小鼠粪便样本阳性率进行统计学差异性分析;将5种小鼠阳性样本的Ct值进行统计描述;采用非参数检验法对5种小鼠Ct值进行差异性分析。结果 共检测粪便样本1 396份,BALB/c、C57BL/6、ICR、KM、BALB/c-nude小鼠的粪便MNV检出阳性率分别为17.65%、39.33%、10.57%、18.32%和27.4%。C57BL/6小鼠的粪便MNV检出阳性率大于BALB/c、ICR、KM小鼠(P<0.05),且BALB/c-nude小鼠的粪便MNV检出阳性率大于ICR、BALB/c小鼠(P<0.05);BALB/c-nude小鼠和C57 BL/6小鼠的病毒载量总体上大于KM小鼠(P<0.001,P<0.05)。结论 MNV-1引物可应用于小鼠MNV感染情况的检测;北京市5种实验小鼠MNV阳性率在10%~40%,其中C57BL/6小鼠和BALB/c-nude小鼠的MNV阳性检出率较高。

Objective To investigate the infection of mouse norovirus(MNV)in experimental mice raised under natural conditions from 19 biological companies in Beijing.Methods The mice used in this study were randomly selected from mice produced by 19 companies,and 14 mice of each strain and batch were combined into one cage,totaling 1396 cages of 19544 mice.The fecal samples from BALB/c,C57BL/6,ICR,KM,and BALB/c-nude mice were collected.TaqMan probe fluorescence quantitative PCR method was used to detect MNV infection of mice with MNV-1 primer,and whether the mice were infected with MNV was determined according to cycle threshold(Ct value).The chi-square test was used to analyze the difference of positive rate among the fecal samples from the five types of mice.The Ct values of the positive samples were statistically described;the non-parametric test was used to analyze the differences in Ct values among the five types of mice.Results A total of 1396 fecal samples were collected.The positive rates of fecal MNV detection in BALB/c,C57BL/6,ICR,KM,and BALB/c-nude mice were 17.65%,39.33%,10.57%,18.32%and 27.4%,respectively.According to the chi-square test results,the positive rate of fecal in C57BL/6 mice was higher than that in BALB/c,ICR,and KM mice(all P<0.05),and the positive rate of BALB/c-nude mice was higher than that in ICR and BALB/c mice(P<0.001,P<0.05).The viral load of BALB/c-nude or C57BL/6 mice was generally greater than that of KM mice(P<0.05).Conclusion MNV-1 primers can be applied to the detection of MNV infection in mice. The positive rate of MNV in five types ofexperimental mice in Beijing ranges from 10% to 40%, among which C57BL/6 mice and BALB/c-nude micehave higher positive rates of MNV than the others.